Shaft positioning mechanism for binary code operation



April 1954 A. H. WULFSBERG ET AL ,676,289 SHAFT POSITIONING MECHANISMFOR BINARY CODE OPERATION Filed Nov. 2, 1951 2 Sheets-Sheet -l Q- 4"]140 r I 26 a I D f7? fll'cflrl'fi MII'IOIID fizzle-yr IN V EN TOR.Ila/arr J], Jcnwzmuorrn April 20, 1954 A. H. WULFSBERG ET AL 2,67

SHAFT POSITIONING MECHANISM FOR BINARY CODEOPERATION Filed Nov. 2, 19512 Sheets-Sheet 2 Pas-17104250 W? W I,

. IN VEN TOR. ans-r M SCI/Ikl/Gafifi lg rumv II. IIMIJMRG 4;- roan-rPatented Apr. 20, 1954 o e-me.

SHAFT POSITIONING MECHANISM FOR BINARY CODE OPERATION Arthur H.Wulfsberg and Horst M. Schweighofer Cedar Rapids, Iowa, assignors' toCollins Radio Company, Cedar Ra of Iowa pids, Iowa, acorporationApplication November 2, 1951, Serial No. 254,514-

This invention. relates in general to shaft: positioning: mechanismsand'in particular to a shaft positioning device which operates on abinary (18;

Sometimes it is desirable toconvertv a binary el'ectrical signal to amechanical shaft position. The electrical signalmaybe coded into: anarbitrary combination of. pulses such as is used in Morse. or Teletypecod-eor'alternately, it. may be: based; on a. binary number systemwherein successive pulses (or? difierent frequencies) have values of 1:,2;. 4-; 8. 2 with the numerical valuestransmitted; being the sum ofthose pulses present the. transmission. The apparatus of this invention;is designed; to. be. operated from such. electrical signals and convertthem to a shaft position.v Theshatt to be controlled might, for example,be: the: main. tuning: shaft of a trans-- mitter'so I that: it may betunednini response to the received signal.-

It is. an object. of.. this: invention. therefor, to: provide aconverting. mechanism. which. changeselectrical. signals from: a. binarycode. to 21 shaft position.

Further obj ects;.advantages; and. features of inventicnxwillbecomeap'pa'nent-irom the follow"-- ingdescription. and; claims whenread in. view of: the: drawingsfin which:

. Figure leis. a. schematic illustration of av system;

having it: different. shaft positions; and.

Figured is. at schematic illustration. of apparattus according. to: thisinvention which. has 256.

difi'erent. shaft. positions;

InFigu-re. 1 at number: or. relays as,. for example,

four are designated I through 13'. The relay' coils. have one sidegrounded:andthe other" side connected to asuitable. receiver whichenergizes eachrelay in responseto theelectrical code; being, For.example; the first: relay L0 transmitted. might correspond to then. or1: digit, andthe electrical impulses received: by the relay l0 willindie catewhich of these two-numbers being trans.-

mitted The second-relay" l.l "mightlcorrespondlto:

center once they'are moveduntil they are moved: to the opposite-positionby the relays; The relays are polarized and may move the contact armseither way. First contacts; l'4-b' through. ITJ-b.

of the switches are-connected together and tea". motor. control relay t8by lea'd- H1. The OCIIBITSTCIQ of relay i is connected tos the positive:side-01- a 13; C. voltage;

The contact The second contacts iW-c' through lT-c of the switches areconnected. together and" to ground.

The two-way contact arms M c through Fl w are electrically connected tocontacts 21, 22:, 23? and 24 which engage wafer switches 28,, Z1", 28and 29'. The wafer switches 26' through 2% are formed with varyingnumbers of projj'ecti'ons.

Wajf er switch 29 has a projection whiclr covers one half' oftheswit'ch; Switch 28- isdiv-id'ed into If our portions with twoprojections and switch 2? has. four projections; Switch iii-has eightprojections.

The contacts 2 I through 24; always engage the switches il'fi'thlough129'; The conductorl9'is'coh. nected': to a wiper; contact for each" of,the switches 25 through 29." The wipercontacts'are designated as 3|through 36. andengage' only the .proj ections oi the switches 26"thrciughZSi They are open circuited' when a; low' portion of theswitches are opposite them.

A second group'of wiper'contacts 3t'through 3c are mounted adjacentitheswitches 25 through" 29 and are connectedttogether' and to ground. Thepair of wiper contacts fbr each switch are mounted apart a distanceequal t'o' the' distance between centers ofa'rfiacenthigh and low segmentsof the switches.

A driving meanstlll as; for example; an elecetrical' motoris connectedto the-positive side of the D. C: supply and itsfopposite sideisconnected to a. t'wo'-wayj switch which is actuated byrelay l8 so whenthe relay is energized'themotoricircuit is closed.

A toothed stop wheel 43? is mounted on shaft. 41 and drives the wafer,su'ritc'hes 26 through 29; His connected tothe'mot'or 41' through asuitable clutch 48. A pawl 45' engages the stop wheel 43 and iscontrolled by relay: l-8.. A positioned element'. 47' is also mounted onthe shaft W and an indicator disc 48 indicates which position is beingutilized. The. driivemeans. andi toothed stop wheel combination issimilar. tothe one described in Patent Number. 2,476,673. and referencemay be. made thereto for a more complete description.

In operation a received. signal its changed to a.v binarycodeto. actuatethe-relays 1.0 through: 13; Suppose}. for; example; that it: is desiredto.- transmittheshaf-t position 9 Thiswouldrequire that the relays Miand H beenergizedswthat-the switch. armsl dmend: III-4L. would moverdowirwarclly.v When'thisoccurs the relay. l'8 will' be energized thusclosingzwthe motor: circuit and. lift ing the: lockingipawl 451mm; the;stop? wheels 43. The motor? than rotate'szthe seeking switches? 26vthrough 29 until an open circuit. occurs in: the

3 control circuit. This occurs when contacts 32 and 33 engage highpositions of their respective switches and simultaneously the contacts3| and 34 are in their open circuit positions. When the open circuit isfound the pawl 45 falls into a notch in the stop wheel. The positionedelement 41 and the indicator 48 are in position number 9. For eachcombination of settings of switches l4 through I! there is acorresponding shaft posi- It is seen that the apparatus of Figure 1allows any one of 16 positions to be transmitted. If a larger number ofshaft positions are desired, a larger number of switches are required.However, with the system shown in Figure l as the number of switches isincreased the smallest unit wafer switch must be divided to have alarger number of segments. For example, if five binary digits areutilized, the switch 26 would have to have 16 projections instead of 8.

The apparatus shown in Figure 2 allows 256 different shaft positions tobe obtained by combining two systems according to claim. The totalnumber of positions then becomes equal to the product of the possiblepositions of the combined systems. If two four switch systems arecombined, 16 times 16 or 256 positions are available.

As shown in Figure 2 each of the systems have wafer switches, controlswitches, toothed stop wheels and motor control relays. A single motor50, however, drives both systems through the clutches and 52. A firstreceiver 53 controls the position of output shaft 54 which is connectedto the upper system, designated generally as 55. The shaft 54 isconnected to an indicator 5! and moves in jumps of IS.

The second system is designated generally as 58 and receives controlsignals from receiver 5a. The output shaft 6| of system 58 drivesindicator 60. The shaft 6| moves in jumps of one.

The shaft positions of shafts 54 and 6| are added together to controlthe positioned element 62. This is accomplished by the difierential 63which adds the shaft inputs. An indicator 64 gives the sum of the inputshaft positions.

An overrun device'66 comprising a cam and follower is connected betweenshaft 61 and differential 63 so that the system 58 never adds more than16 units to the output. This prevents the indicator 64 from indicating awrong position.

The cam and follower serve two functions:

(1) Speed reduction.Since system 56 moves in jumps of 16 units per 22.5degrees while system 58 moves in jumps of 1 unit per 22.5 degrees, therelative values of rotation in units per degree must be made equalbefore addition in the differential.

Thus, the cam follower is made to have an angular travel of 1 s thetravel of the cam 66, or 1 unit per 22.5/16 degrees equals 16 units per22.5 degrees, the same as shaft 54.

(2) Non-cumulative rotation.-When shaft 61 makes one completerevolution, dial 6|] returns to the same value. However, if shaft 6|(after suitable gear reduction) is fed directly into the differential,one revolution of the shaft would advance dial 64 by 16 units,accumulating an error of 16 units each time shaft 61 passed from "5 to0. The cam 56 prevents this.

Although this invention has been described with respect to particularembodiments, it is not to be so limited as changes and modifications maybe made therein which are within the full intended scope of theinvention as defined by th appended claims.

We claim:

1. Shaft positioning apparatus for controlling the position of a shaftcomprising a plurality of relays, a first plurality of contact armscontrollable by said relays and movable between first and secondcontacts, the second contacts connected electrically together and toground, the first contacts connected electrically together, a motorcontrol relay connected electrically to the first contacts, the oppositeside of said motor control relay connected to a power supply, a drivingmeans connected to the power supply, a motor switch actuated by saidmotor control relay and connected between the driving means and ground,a toothed stop-wheel mounted on the output shaft of said driving means,a pivoted pawl engageable with said toothed stop-wheel and connected tosaid motor relay, a plurality of wafer switches connected to the outputshaft of said driving means, a first one of said wafer switches formedwith eight projections spaced equidistance about the periphery, a secondof said wafer switches formed with four projections spaced equidistanceabout the periphery, a third one of said wafer switches formed with twoprojections formed eq-uidistance about the periphery, a fourth waferswitch formed with one projection, a second plurality of contact armsconnected respectively to the first plurality of contact arms andengageable with the wafer switches at all times, a first group of wipercontactsmounted about the peripheries of said wafer switches andengageable with the projections, said first plurality of wiper contactselectrically connected together and to the motor control relay, a secondplurality of wiper contacts mounted adjacent the wafer switches andeneageable with the projections of the wafer switches, and said secondplurality of wiper contacts connected together electtrically and offsetalong the periphery from the first Wiper contacts by one projectionwidth.

2. Shaft control mechanism for positioning a controlled element to anumber of distinct positions comprising, a driving means, a toothed stopwheel connected to the output shaft of said driving means, thecontrolled element mounted on the output shaft of said driving means, apawl engageable with the teeth of said toothed stop wheel, a motorcontrol switch connected to said driving means, a motor control relayconnected to actuate said pawl and said motor control switch, aplurality of wafer switches connected to the output shaft of the drivingmeans and formed with a varying number of projections, a first plurality of. wiper contacts connected electrically to the motor controlrelay and engageable with the projections of said wafer switches, asecond plurality of wiper contacts connected to ground and engageablewith the projections of said wafer switches, said second plurality ofwiper contacts offset along the periphery from the first wiper contactsso that when a first wiper contact engages a projection thecorresponding second one is disengaged, a first plurality of contactsconnected together and to the motor control relay, a second plurality ofcontacts connected together and to ground, a plurality of contact armsmovable between the first and second plurality of contacts, a thirdplurality of wiper contacts engageable at all times with the waferswitches and connected respectively to the plurality of contact arms,and a plurality of control relays mounted adjacent said contact arms tocontrol their position in response to control information.

3. A shaft positioning control system comprising, a driving meansconnected to the controlled shaft, a toothed stop wheel mounted on theoutput shaft of said driving means, a pivotally sup ported pawlengageable with the toothed stop wheel, a motor control relaymechanically connected to said pawl to control its position, a motorcontrol switch actuated by said motor control relay, one side of saidmotor control relay connected to the positive side of a voltage sup ply,a plurality of wafer switches connected to the output shaft of thedriving means, said plurality of wafer switches formed with varyingnumbers of projections, a first plurality of wiper contacts mountedadjacent the wafer switches and engageable with the projections, saidfirst plurality of wiper contacts connected electrically together and tothe opposite side of the motor control relay, a second plurality ofwiper contacts engageable with the projections of the wafer switches andconnected electrically together and to ground, a plurality of switcheshaving first and second contacts, the first contacts connected togetherand to the one side of the motor control relay, the second contactsconnected together and to ground, contact arms of said con trol switchesmovable between the first and second contacts, a plurality of thirdwiper contacts always engageable with the wafer switches and connectedrespectively to the contact arms, and a plurality of control relaysmounted adjacent the control switches to control the positions of thecontact arms.

4. An apparatus for obtaining a plurality of shaft positions equal tothe product of the positions available with the combined individualsystems comprising a plurality of shaft positioning control apparatusesaccording to claim 3, a differential receiving the output shaftpositions of said plurality of control apparatuses and adding them toobtain the combined position.

5. An apparatus for obtaining a plurality of shaft positions comprising,a first control system according to claim 3 which corresponds to thelower incremental steps for the controlled shaft, a second controlsystem according to claim 3 which corresponds to the larger incrementalcontrol steps, a single turn overrun device connected to the output ofthe first control system, and a differential receiving shaft inputs fromthe second shaft control system and the overrun device to add them toobtain a number of positions equal to the product of the positionsavailable with the individual first and second control systems.

6. Means for controlling the angular position of an output shaftcomprising, a driving means connected to the output shaft, a toothedstopwheel mounted on the output shaft, a pawl pivotally supportedadjacent the toothed stop-Wheel and engageable therewith, a plurality ofwafer switches each formed with a different number of projectionsmounted on the output shaft, a motor control relay mechanicallyconnected to said pawl, a motor control switch controlled by the motorcontrol relay, a first plurality of wiper contacts connected to saidmotor control relay and engageable with the projections of the waferswitches, a second plurality of wiper contacts connected together and toground and engageable with the projections of said wafer switches, saidfirst and second wiper contacts offset about the peripheries so thatthey alternately engage the projections, a third plurality of wipercontacts engageable with the wafer switches at all times, a plurality ofcontrol switches with their contact arms connected respectively to thethird wiper contacts, a first plurality of contacts of said controlswitches connected electrically together and to the motor control relay,a second plurality of second contacts of said control switches connectedelectrically together and to ground and an actuating relay mountedadjacent each control switch to control its position in response tocontrol signals.

'7. An apparatus for controlling the position of a shaft comprising apair of shaft position control systems according to claim 4, the outputshaft position of the first control system added to the output shaftposition of the second control system by means including a differentialand an overrun device, connected between the output shaft of the secondcontrol system and the differential.

8. Shaft positioning mechanism comprising, a pair of wafer switches, thefirst of said wafer switches formed with a plurality of projectionsspaced about its outer periphery, the second wafer switch formed with adifferent number of projections spaced about its periphery, a first pairof wiper contacts engageable respectively with the projections of thefirst and second wafer switches, a second pair of wiper contactsengageable respectively with the projections of the wafer switches butoffset along the periphery from the first pair of wiper contacts, athird pair of wiper contacts engageable at all times with the waferswitches, a pair of control switches having contact arms movable betweena pair of contacts, the contact arms connected, respectively, to thethird pair of wiper contacts, the first contacts connected together andto the first pair of wiper contacts, the second contacts connectedtogether and to ground, a motor control relay with one side of itscontrol circuit connected to the first pair of wiper contacts and theother side connected to a power supply, a driving means connected to oneside of the power supply, the motor control switch connected betweenground and the other side of the driving means, a toothed stop-wheelmounted on the output shaft which is attached to the driving means, apawl pivotally supported to engage the toothed stop-wheel, said pawlcontrollable by the motor control relay, and the pair of switches drivenby the driving means through the output shaft.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,476,673 May et al July 19, 1949 2,565,334 Weingarden June 9,1949

